The present invention relates to an electrical connector system for terminating a plurality of conductors. More particularly, the invention relates to a connector system which enables the center conductors of coaxial cables to be connected separately to the signal terminals of a connector by a simultaneous operation, without intervening individual coaxial cable preparation or aligning steps, and with a minimum of connector terminal structure. The connector system also enables more efficient termination of the coaxial cable shields.
In the prior art, connectors for terminating a plurality of shielded coaxial cables typically have a connector body with recesses for holding the signal terminals of the connector and for channeling the center conductors to the signal terminals. The terminals for such connectors typically are discrete rigid elements with various structural features that affect the termination method of the connector. For example, some terminals are equipped with tangs designed for insulation penetration, as shown in Yaegashi et al., U.S. Pat. No. 4,365,856, to avoid the loss of time normally required for individually stripping the wires. A primary disadvantage of such terminals is the large start-up expense for the special equipment required to tool such structurally complex terminals. Typically, special equipment is also required to mold multi-chambered insulative bodies to contain such terminals. Additional continuing expenses are associated with large scale manufacturing of numerous discrete terminals involved in multi-step fabrication processes (typically stamping and forming).
A few coaxial cable connectors do not have the disadvantages cited above. For example, in Schmitz et al., U.S. Pat. No. 4,335,364, the signal terminals are thin layers deposited on a connector board. Start-up expenses are kept low because conventional photo-lithographic equipment is used rather than specially built tooling equipment. Additionally, the need for multichambered insulative bodies is eliminated. Less expense is associated with depositing or etching the terminals in bulk, simultaneously, rather than individually fabricating and forming them. The disadvantage of such coaxial cable connectors is that they are not readily adaptable to terminating a plurality of cables. If such termination were attempted, the termination time would be excessive because, between each connecting step, where the center conductor of a cable is connected to a signal terminal, an aligning step would be required for aligning the next cable for connection.
Other connectors have multi-function signal terminals that do permit aligning of all of the conductors at once for subsequent connection. For example, in Lockard, U.S. Pat. No. 4,579,404, the conductor aligning step is performed simply by pressing the cables between retaining walls of the signal terminals, thus establishing an interference fit. The center conductors of the cables may then be connected to the signal terminals, for example, by laser welding, without intervening cable aligning steps. Such connectors exemplify efficient use of one element, the signal terminal, which performs a retaining function, a connecting function, and, in Lockard, an extending function (for edge card connection). However, such connectors still require extra expense for special terminal tooling equipment and extra continuing fabrication expense.
Although the discussion so far has focused on the time and expense associated with the conductor alignment and terminal connection steps, there is also time and expense associated with the conductor preparation step before the conductor is even positioned on the connector. Typically, for example, the outer dielectric jacket of a coaxial cable must be stripped to expose the metallic shield underneath, and the inner dielectric layer must be stripped to expose a portion of the center conductor. Inventions such as Yaegashi et al., U.S. Pat. No. 4,365,856, rely on insulation penetration to decrease the time spent individually stripping conductors. With such inventions, the tangs on the signal terminals penetrate the inner dielectric layer to reach the center conductor, thus bypassing the preparatory step of removing the inner dielectric layer. Besides the disadvantage, observed above, of complicating the terminal structure, such a method irreversibly affects the physical integrity of the conductor and produces an extra length of conductor extending beyond the connection point